1. Field of the Invention
The present invention relates to a material, a solid electrolyte and a photovoltaic device using the same. More particularly, the present invention pertains to a novel hole transporting material that has advantageous electrically conductive properties so that it can be used as a solid electrolyte in a photovoltaic device.
2. Description of the Related Art
A solar cell is a photovoltaic device for converting sunlight into electrical energy. Their ability to convert sunlight into electrical energy is unlimited. These are also environmentally friendly and hence their popularity has been growing over time. In particular, the use of photovoltaic cells in portable information devices, such as portable computers, portable phones, and personal digital assistants, renders these portable information devices versatile.
Mono- and poly-silicon solar cells have been frequently used in a variety of applications. However, the silicon solar cell is disadvantageous since the production costs of silicon are high, the raw materials are expensive, and because it is difficult to improve the conversion efficiency of solar energy into electric energy.
Accordingly, interest in solar cells that are capable of being produced inexpensively from organic materials has increased. In particular, dye-sensitized solar cells that have low production costs are of interest. The dye-sensitized solar cell is a photo electrochemical solar cell that comprises a porous semiconductor layer including nanoparticles attached to a transparent electrode, a light absorption layer including a dye adsorbed on the semiconductor layer, and an electrolytic solution for oxidation and reduction charged between the two electrodes. The dye-sensitized solar cell is advantageous in that the photoelectric conversion efficiency thereof is high and the production cost is low.
However, since the dye-sensitized solar cell is a wet-type cell that comprises a liquid electrolyte, its photoelectric conversion efficiency is reduced over time due to leakage of the electrolytic solution or volatilization of the electrolytic solution. Thus the reliability and long-term stability are reduced.
In order to avoid the problems of the wet-type solar cell, many studies have been conducted into solar cells that employ a solid polymer electrolyte used as a hole transporting material instead of the electrolytic solution.